GSBS Student Publications

Title

Hemodynamic and metabolic changes induced by cocaine in anesthetized rat observed with multimodal functional MRI

Student Author(s)

Karl Schmidt

GSBS Program

Neuroscience

UMMS Affiliation

Department of Psychiatry, Center for Comparative Neuroimaging

Date

3-22-2006

Document Type

Article

Medical Subject Headings

Algorithms; Anesthesia; Animals; Blood Volume; Brain Chemistry; Cerebrovascular Circulation; Cocaine; Data Interpretation, Statistical; Hemodynamics; Hypercapnia; Injections, Intravenous; Magnetic Resonance Imaging; Male; Metabolism; Oxygen; Rats; Rats, Sprague-Dawley; Reward

Disciplines

Life Sciences | Medicine and Health Sciences | Neuroscience and Neurobiology

Abstract

RATIONALE: Physiological changes (such as heart rate and respiration rate) associated with strong pharmacological stimuli could change the blood-oxygenation-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) mapping signals, independent of neural activity.

OBJECTIVES: This study investigates whether the physiological changes per se associated with systemic cocaine administration (1 mg/kg) contaminate the BOLD fMRI signals by measuring BOLD and cerebral blood flow (CBF) fMRI and estimating the cerebral metabolic rate of oxygen (CMRO(2)) changes.

MATERIALS AND METHODS: BOLD and CBF fMRI was performed, and changes in CMRO(2) were estimated using the BOLD biophysical model.

RESULTS: After systemic cocaine administration, blood pressure, heart rate, and respiration rate increased, fMRI signals remained elevated after physiological parameters had returned to baseline. Cocaine induced changes in the BOLD signal within regions of the reward pathway that were heterogeneous and ranged from -1.2 to 5.4%, and negative changes in BOLD were observed along the cortical surface. Changes in CBF and estimated CMRO(2) were heterogeneous and positive throughout the brain, ranging from 14 to 150% and 10 to 55%, respectively.

CONCLUSIONS: This study demonstrates a valuable tool to investigate the physiological and biophysical basis of drug action on the central nervous system, offering the means to distinguish the physiological from neural sources of the BOLD fMRI signal.

Rights and Permissions

Citation: Psychopharmacology (Berl). 2006 May;185(4):479-86. Epub 2006 Mar 21. Link to article on publisher's site

Related Resources

Link to Article in PubMed

Journal Title

Psychopharmacology

PubMed ID

16550388